Projects completed now include study of auditory brainstem responses in pervasive developmental disorders, a PET-scan FDG study of autism, a clinical follow-up study of autism, a comparative study of psychiatric symptoms in autistic adults, schizophrenics, manics, and normal controls, and a study of conceptual problem-solving in unusually high-functioning autistic adults. Ongoing projects include a volumetric CT-scan study of autism, a study of CT-scan asymmetries in autism, neuropsychological studies of high-functioning autistic adults, autonomic nervous system studies of autism, and a correlational study of behavioral symptoms in autistic children and adults with widely varying intelligence and language. In addition, we are recruiting more autistic adults for PET-scans in order to achieve a number adequate to apply a correlational analysis to look at functional associations between brain regions. Normal control data have now been completely collected for all but the autonomic nervous system studies, where data collection is still in progress. Data on the other projects are being scored and statistically analyzed. New projects include a series of anatomical and physiological studies of learning disabilities in adults and children. Test batteries for use in subject selection, event-related potentials, EEG spectral analyses, and cerebral blood flow are nearly completed. Initial contacts with various school programs have been made to begin work on the recruitment of subjects. Contacts with personnel at Columbia University who are planning to do related epidemiological studies have been made. Initial plans have been made to screen and recruit subjects identified as part of this larger project.